This invention relates to a baking method and apparatus for determining the distribution of flowable material that is being deposited by gravity onto a surface that is disposed below the apparatus that is distributing the flowable material. More particularly, the present invention relates to a sampling method and device to determine the distribution of salt, spices, flavorants, oils, oil-solid mixtures, water-solid mixtures, icings, enrobing coatings and other related coatings that are deposited onto food articles that have been baked, or that are to be baked, and that are being conveyed below the device distributing the flowable material.
In the production of many baked food items such as cereals, cookies, crackers, biscuits, candies and snack products, various flowable substances are deposited onto the food item during its production. These materials are deposited both before and after baking. Regardless of when applied, it is important that the application be uniform across the entire food product. As the food product passes on a conveyor located below the device that is distributing the flowable material, a preset amount of the solid, liquid or mixed coating is allowed to flow by gravity downward onto the food product. This application of the flowable material must be uniform across the full width of the food product located on the conveyor belt and must be uniform along the length of the food product as it moves along the conveyor belt. Any significant variations will cause the final product to have a varying taste and/or appearance. This creates a problem since the product is a single product that is packaged under a single brand name. Consumers have usually developed a taste for a particular product. Consumers are also usually well aware of the appearance that the product should have when it is to be consumed. Consequently, it is important that all of the product preparation steps be kept as constant as possible. This includes the raw materials that are used, mixing techniques, baking procedures, and as pointed out above, the application of various coatings.
A convenient manner in which to deposit a solid flowable material that is passing below on a conveyor belt is to apply the material by gravity feed. That is, the flowable material drops downwardly by gravity after having been metered through a dispenser. For solids such dispensers can be of a type where the material is held in an elongated hopper where the length of the hopper is at least equal to the width of the conveyor belt. The hopper will usually have a truncated V-shape with a series of holes in the lower truncated end whereby flowable material can exit the dispenser. Also located in the dispenser will be a means to agitate the flowable material to assure that it does not pack and agglomerate. In many cases this agitating means will consist of a rotating shaft that carries a series of projections or tines. In the alternative, this rotating shaft can carry a plurality of linear or spiral scraper flanges along the entire length of the shaft.
A method for applying a liquid is to provide a linear nozzle that extends the width of the conveyor belt. This linear nozzle is essentially a tubing with a narrow slit. The tubing will have a length at least equal to the width of the conveyor belt. The liquid will fall through this slit with operation of the nozzle being at atmospheric pressure or at a slightly elevated pressure. The liquid, after leaving the nozzle, will fall downwardly by gravity.
When the substance to be applied is a fairly viscous liquid it can be extruded downwardly from an overhead mounted linear extruder. The extruder will have an extrusion head that is the width of the conveyor belt. The viscous liquid extrudes through an opening of a set dimension and is deposited by gravity onto a surface disposed below the extruder head.
Regardless of the flowable material dispenser that is used, and the technique that is used to keep the flowable material mixed and uniformly flowing from the dispensing region, there is always the need that the flowable material be uniformly distributed from the dispenser onto the product that is passing below the dispenser
The devices of the present invention are directed to periodically determining whether the flowable material dispenser is functioning properly. This device in the embodiment to sample solid and liquid materials consists of an array of chambers that from time-to-time pass below the dispenser. The array of chambers will collect a representative sample of material from the dispenser. Each chamber will collect a certain amount of material. If the dispenser is dropping flowable material uniformly across the conveyor belt, each chamber will contain essentially the same amount of flowable material. The amount of flowable material in each chamber is determined by weighing each of the chambers to determine the amount of flowable material in each chamber. In the alternative, various wet chemistry techniques can be used. For instance, if the flowable material is salt, a given amount of water can be added to each chamber and the chloride ion or sodium ion concentrations determined. Or, if the flowable material has a color, a solvent can be added and the amount of flowable material in each chamber determined photometrically against known standards. Yet other analytical techniques can be used.
When the flowable material is a viscous liquid such as a liquid/solid mixture, the sampler device will be a plurality of flat plates that are held together in a frame. Each flat plate will usually be approximately of the same size as the item onto which the viscous flowable material would be deposited. After the material has been deposited onto the sampler, the sampler is then dismantled and each of the plurality of weight of the viscous material deposited onto each part of the sample.
The primary objective is to be able to periodically determine the operation of a flowable material dispenser without having to stop the production of the product. It is important that the dispenser, nozzle or extruder continuously dispense a uniform amount of material. During the operation of the product line there is a constant visual inspection of this part of the process. However, visual techniques are not fully effective. The prior art has not extensively addressed this problem.
U.S. Pat. No. 3,487,427 discloses a method and apparatus for sampling ore. In the method disclosed in this patent, sample collectors move along a conveyor belt and receive from a loading station the same ore material that is otherwise being deposited onto the conveyor belt. The sample collectors extend across the full width of the conveyor belt. In the method described in this patent the sample collectors would be arranged at various intervals determined by the frequency of sampling that is desired. However, the sample collector of this patent consists of a single container rather than a container with a plurality of chambers that would collect a sample so that the distribution of a material being deposited downwardly can be determined.
U.S. Pat. No. 3,902,370 discloses a sample collector. This is an open-topped, single chamber sample collector which is specially designed to be placed on a conveyor belt and is adapted to receive flowable material which The sampling container consists of a curved bottom portion but with parallel side walls and end walls. This sample collector also has additional structure at the front and rear ends of the sample collector in order to stabilize the sample collector on the conveyor belt. This sample collector being of a single chamber type would not provide data on the distribution of a material being dispensed via a gravity feed.
U.S. Pat. No. 3,943,771 discloses a sampling device for sampling a powder that is flowing freely down through a conduit. This sampling device consists of a rotating disk which extends partially into the conduit and thereby collects some of the material as a sample. As the disk rotates, the material is passed under a viewing window for inspection. After inspection, the sample is returned to the conduit and will become a part of the product stream. This patent does disclose a method for sampling a downwardly flowing flowable material. However, structurally and operationally it will not determine the distribution of a flowable material over a given area.
U.S. Pat. No. 4,574,645 discloses an apparatus and a method for sampling a flowable material that is falling downwardly. The apparatus consists of a tubular device which extends into a conduit. The tubular device has an opening disposed such that when the tubular device is rotated to a first position it collects downwardly flowing material and deposits this downwardly flowing material into a container which is exterior to the conduit in which the material is being sampled. When this tubular device is rotated about 180.degree., a baffle prevents flowable material from flowing into the tublar device and thus a sample is not taken at that point in time. Using this device, samples can be taken periodically of a material that is flowing downwardly through a conduit. Samples that are being taken are deposited into a single sampling container rather than the use of an array of sampling containers.
U.S. Pat. No. 4,522,076 discloses a method for collecting samples of material from a conveyor belt. The method has the advantage of sampling the full width of the conveyor belt. This method consists of the use of a collector conveyor belt for collecting a desired sample. After a sample has been collected, the collector conveyor belt is retracted from the region of the main conveyor belt so that the conveyor belt can continue to deliver the material to a product station. However, this method will collect a single sample rather than a distribution of a downwardly falling material.
Russian Patent No. 789061 discloses a sampler for taking samples of free-falling materials. In this device, a material such as a flowable material is falling downwardly through a conduit. A sampler is disposed within the conduit, which sample has a slotted end piece. This slotted end piece is moved across the flow of the falling material in order to gather a sample. The sampler is in the shape of a parallelogram. This device is adapted for continuously taking samples of material and for providing these samples for evaluation exterior to the conduit in which the flowable material is flowing. Although this patent discloses the sampling of a downwardly flowing flowable materials, it does not use a plurality of sampling containers and would not provide data on the distribution of a particulate material that is being deposited by gravity onto a lower surface.